I'm not knowledgeable in the classical pieces of artwork, however for fanart I do have some favorites.

I'm quit fond of the way Marc Simonetti illustrates A Song Of Ice And Fire, he sort of brings that world to life in a way that's closer to the books than the show does. The amount of detail, from the Iron Throne to specific scenes, adding a kind of otherworldly and slightly unsettling appearance in certain pieces. I especially loved the House of the Undying one that unfortunately wasn't featured in the show, and wished it was, because it was intentionally creepy. Similarly, Michael Komarck has done nice pieces as well, particularly the ones of Jamie on the Throne, Sansa at the Eyrie, and the infamous Ned Stark at the Winterfell Godswood.

Back in the days of Harry Potter fandom, there were plenty of great artists, but there was a one fanartist by the name of Seviet (Marta T) who did fantastic pieces of art for the series. I loved her artists style of the characters, it seemed very unique and it kind of went well with the atmosphere of the books and brought particular scenes to life. Unfortunately she has deleted her journal and the website she frequently posted on has disappeared, but thankfully her work continues to live on and be appreciated elsewhere online.

Most recently I've been enjoying some Hobbit fanart, specifically Thorin and Bilbo/Thorin related. Ewebean has a very unique style that I really love, particularly the way she draws Bilbo little upturned nose. This person also does some fantastic pieces. Radiocrist as well, specifically as it ranges from the silly to all the cuteness and sweetness, and the hotness, to just heartbreaking. This is another current favorite from another fanartist in the fandom, because I love it when things get switched up and Bilbo gets to be the big spoon while Thorin basks at being little spoon. And really, the art is just too adorable. ♥

Honestly, there are some really amazing pieces of fanart featured, especially on Tumblr, and not just from The Hobbit. I wish I could list all the ones that I really admire. Perhaps I should just make a compilation post in order to keep track of them all, since there's so many talented people in fandom.

For general non-fandom related art, I do have an interest and admiration for street art. Whether legal or illegal, underground pieces or paid murals on the sides of buildings, the graffiti culture is something I'm fascinated by since it has its own rules and its own kind of beauty to it. And while there are some negative associations attached, there is quite more to the culture than just that. I've been reading up on and watching some documentaries on the subject, and while I'm hardly an expert it's really quite intriguing to me, especially when it comes from speaking out against what is happening in the world, socioeconomically and politically, and about personal expression on certain issues that otherwise would be silenced. It has its own language and history that is fascinating to me.